The Clinical Laboratory and Biomarkers Core will facilitate and coordinate access to laboratory expertise. The overall goal of this core is to assure that all JHU HIV investigators, particularly junior investigators, will have the greatest possible access to expertise on the appropriate use of and the laboratory assays required for addressing their research questions. This Core will also establish and maintain a biomarker specimen repository for storing and accessing biological specimens. The Core will interact with the Administrative, Developmental, Clinical, Prevention and Biostats, Epidemiology and Methods cores, as well as with the Scientific Working Groups, to assure access to cutting edge and quality-assured laboratory methodologies to junior and new investigators conducting research on HIV in Baltimore and globally.